[en] The chemical and radiolytic interaction of tritium with oils produces a variety of tritiated compounds. To understand the metabolic behavior and possible dosimetric consequences of tritiated oil contamination, the course of urinary tritium activity in hairless rats exposed to tritiated pump oils has been investigated. The contaminated oil was applied on the animals' skin, and the excretion of tritium in urine was assayed for 112 days, allowing for the measurement of long-term tritium retention and excretion in the body. Tritiated oil deposited on the skin provides an input of OBT (organic-bound tritium) and HTO to the body. The excretion of HTO was found to be biphasic with exponential function half-lives of 3.3 ± 0.4 days and 25.5 ± 3.5 days. Elevated levels of OBT were noticed in the urine. The excretion of OBT was analyzed in terms of fast, slow and long-term components. OBT had a much shorter effective time constant than HTO. The half-lives for these components were 1.0 ± 0.1 day, 5.4 ± 0.6 days, and 31.4 ± 1.9 days, respectively. The long-term retention of tritium in the body is attributed to metabolism and the assimilation of tritiated compounds into the body. (Author) (3 figs., 3 tabs., 11 refs.)